Figure 3-14. The vulva, the external female genitalia.
f. The Mammary Glands (Breasts). The mammary glands may be considered
an accessory of the reproductive system since they secrete milk for the nourishment of
infants. They extend vertically from the second to the sixth rib and transversely from the
lateral margin of the sternum to the anterior border of the axilla at about the level of the
fourth costal cartilage. Each breast is a cone-shaped mass of tissue, presenting near
its center a papilla-like projection, the nipple. The nipple contains the openings of the
milk ducts and is surrounded by a pigmented area of skin called the areola. Glandular
tissues embedded in a large amount of connective tissue and varying amounts of fat
comprise the internal structure. The glandular tissue consists of 15 to 20 lobes, each
with its own draining duct. In the region of the nipple, each duct is dilated to form an
ampulla that serves as a reservoir for the milk secretion before opening finally on the
surface of the nipple. Endocrine secretions regulate the production of milk by the
mammary glands.
MD0956
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